installed-tests: fix deactivated GIMarshalling test suite
installed-tests: fix deactivated GIMarshalling test suite

I believe when the installed test suite got created, the way JS files
are loaded changed. That resulted in the window object being different
from the scope of the test files, leaving that particular test suite
disabled.

https://bugzilla.gnome.org/show_bug.cgi?id=728004

mtwebster/cjs,pixunil/cjs,mtwebster/cjs,pixunil/cjs,pixunil/cjs,pixunil/cjs,mtwebster/cjs,pixunil/cjs,mtwebster/cjs,mtwebster/cjs